Conventionally, as for an internal combustion engine of an automobile and the like, various ideas have been devised to improve fuel efficiency thereof. For example, a fuel/air mixture was optimized for complete combustion by mixing an additive with fuel, or by coating an air filter with a coating agent so as to improve fuel efficiency.
Generally, a radiator is disposed near the internal combustion engine in order to cool the internal combustion engine and improve thermal efficiency; however, as for a coolant added into the radiator, various devices have been made to improve the fuel efficiency as well. For example, in Patent Document 1, fuel efficiency is improved without manipulating the internal combustion engine or an electrical system using the coolant containing an antifreeze solution, a microorganism co-cultivation extraction liquid, and the like. Also, in Patent Document 2, a liquid containing a powdered tourmaline is used as the coolant inside the radiator, so that the coolant having an electrical property is discharged into an outside of an engine cylinder, and a fuel mix gas inside the cylinder is ion-activated to promote the complete combustion of the fuel mix gas so as to improve horsepower and fuel efficiency.
Furthermore, in Patent Document 3, there is disclosed an additive for a radiator which improves the fuel efficiency of the internal combustion engine and reduces an environmental load by being added to the coolant inside the radiator. According to the Patent Document 3, the inside of an engine combustion chamber is negative-ionized by adding the additive for the radiator comprising a mixture of powders of carbon-based semiconductor material and anion ore, which have a particle diameter in micrometer units at the maximum, and ethylene glycol to the antifreeze solution so as to carry out the complete combustion of the fuel/air mixture, thereby improving fuel efficiency.
There are many unclear points regarding a process for improving fuel efficiency; however, unlike conventional additives or coating agents for gasoline or the air filter, an attempt to improve fuel efficiency of the internal combustion engine of the automobile and the like using the additive for the radiator such as the Patent Document 3 is expected as a new research and development field.
On the other hand, since platinum which is a noble metal is highly stable chemically, is hardly oxidized, and has a high melting point of 1769° C. (physics and chemistry dictionary), the platinum is used for various applications such as crucible, platinum loop, weights and measures standard (prototype kilogram, prototype meter), an electrode, or the like. For example, in a platinum electrode, since the platinum is chemically stable so as to have the advantage that it is resistant to chemical change occurring on an electrode surface or at an electrode periphery, the platinum electrode is widely used for various types of oxidation-reduction reaction, a reforming reaction, or the like, and it is known that it exhibits excellent activation as a catalyst as well compared to other metal catalysts.
As mentioned above, since the platinum has high activation as the catalyst, a large quantity of platinum is used for the automobile as an exhaust gas purification catalyst. Furthermore, due to high durability thereof, platinum is frequently used in parts exposed to harsh environments such as a spark plug, an exhaust air sensor, or the like of the automobile in the same manner.
On the other hand, recently, Patent Document 4 discloses a colloidal solution containing a nano-sized platinum particle, and combined with various platinum applications as mentioned above, a research development using a colloidal nano-sized platinum solution has received attention.
Also, recently, catalysis of a nano-sized gold particle has received attention, and for example, Patent Document 5 provides a technology of immobilizing gold fine particles on a carrier comprising a metallic oxide composed of mainly titanium, and using it as the catalyst in various types of applications. Moreover, Patent Document 6 introduces a method of manufacturing a gold fine particle having an average particle diameter of 3 nm or less by mixing a reducing agent solution with a gold ion solution (including a colloidal state).
Patent Document 1: Japanese Unexamined Patent Application Publication No. H08-283704
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2003-161152
Patent Document 3: Japanese Unexamined Patent Application Publication No. 2007-162546.
Patent Document 4: Japanese Unexamined Patent Application Publication No. 2008-56592
Patent Document 5: Japanese Patent No. 2615418
Patent Document 6: Japanese Unexamined Patent Application Publication No. 2011-94234